.\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
.\"
.\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
.\" Distributed under GPL
.\" %%%LICENSE_END
.\"
.TH CASINH 3 2021-03-22 "" "Linux Programmer's Manual"
.SH NAME
casinh, casinhf, casinhl \- complex arc sine hyperbolic
.SH SYNOPSIS
.nf
.B #include <complex.h>
.PP
.BI "double complex casinh(double complex " z );
.BI "float complex casinhf(float complex " z );
.BI "long double complex casinhl(long double complex " z );
.PP
Link with \fI\-lm\fP.
.fi
.SH DESCRIPTION
These functions calculate the complex arc hyperbolic sine of
.IR z .
If \fIy\ =\ casinh(z)\fP, then \fIz\ =\ csinh(y)\fP.
The imaginary part of
.I y
is chosen in the interval [\-pi/2,pi/2].
.PP
One has:
.PP
.nf
    casinh(z) = clog(z + csqrt(z * z + 1))
.fi
.SH VERSIONS
These functions first appeared in glibc in version 2.1.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.ad l
.nh
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.BR casinh (),
.BR casinhf (),
.BR casinhl ()
T}	Thread safety	MT-Safe
.TE
.hy
.ad
.sp 1
.SH CONFORMING TO
C99, POSIX.1-2001, POSIX.1-2008.
.SH SEE ALSO
.BR asinh (3),
.BR cabs (3),
.BR cimag (3),
.BR csinh (3),
.BR complex (7)
